The shadow business secretary has described the aim of Labour’s Brexit policy as “have our cake and eat it”, while conceding it would be difficult to keep the benefits of single market and customs union memberships without major concessions.

Rebecca Long-Bailey said maintaining access to, or even membership of, the customs union and single market could prove problematic given the political realities of Brexit, but said Labour must be flexible in such areas.

Asked on BBC1’s Sunday Politics about single-market membership after Britain leaves the EU, Long-Bailey said the party must “respect the result of the referendum, respect the will of the people in terms of having greater control over our laws, greater control over our borders”.

She said: “If we could negotiate an agreement on remaining within the single market that dealt with all of those issues then that would be fantastic. But whether that’s likely remains to be seen.”

Worries over the free movement of people and control over laws was “one of the key positions that was set out in the referendum,” Long-Bailey said.

“If we could negotiate membership of the single market whilst dealing with free movement and dealing with the other issues then that would be great, but I think that’s probably unlikely and we’ll have to be looking at a more flexible approach that maintains the benefits that we currently have in the single market whilst perhaps not being a member.”

On the customs union, Long-Bailey said: “Again, the position is very similar. We want to maintain the benefits that we currently have within the customs union – we want to have our cake and eat it, as do most parties in Westminster.”

Asked if that put her in the same policy position as Boris Johnson, who first used “cake and eat it” as his approach for Brexit, Long-Bailey said: “We need to be flexible. We’ve got to not cut our nose off to spite our face.”

Part of this, she said, should be an attempt for the UK to keep the benefits of the customs union while also being able to negotiate its trade deals.

Asked if such an approach was untenable, she replied: “That’s the whole point of negotiations. Not to be untenable, but to negotiate the position. Our end goal is to maintain the benefits we currently have as part of the customs union and the single market.

“The machinery that we use to do that, whether it’s through outside agreements or negotiating some form of amendment settlement as part of membership, that’s a moot point quite frankly. But we need to make sure that we have the same benefits.”